Arrow track that travels under station and ends [other]

I'm sure many of you have seen the small piece of track that is next to the brake run and on the opposite side of the transfer table. It dips down and travels under the station. Corkscrew, Iron Dragon, and Magnum all have them. It seems obvious that they were meant to let a train travel to a maintenance area. However, I have never seen these used. No videos are out there of them in use. I've seen pictures of them using forklifts or small cranes to take trains off the transfer track in the off season. My question is has anyone ever seen them use this feature? I have asked several people who I thought would know but didn't. I've studied them while standing near them, notching cobwebs on them made it obvious they are seldomed used, if ever. I wonder why? Does anyone know or have pics of them being used?